Motor driven vehicles such as trucks, boats and the like, are driver operated away from supervision. Such vehicles are large energy users making them very costly to operate. Control is required to assure safe as well as energy and maintenance saving operation. Increasing complexity requires that more and more functions be controlled. It is desirable to continuously analogue record certain of the more critical conditions. Others may be recorded in an on/off manner to observe whether or not undesirable conditions exist.
Presently available recording instruments use a plurality of styli for the recording of more than one variable. However, because such instruments mounted in the vehicles must be small, there is an obvious constraint of space and the recording area on the charts is quite limited. This in turn, limits the number of styli which can be used to record different functions on the chart.
Another method used to increase the recording space on a chart, is to record from both sides of the paper disc forming the chart by means of opposed styli. Although this arrangement overcomes the problem to a certain extent, it still does not maximize the recording area available on the chart.
Present recording systems assign a stylus for each parameter or operating condition to be recorded. Therefore the number of variables which can be recorded is restricted due to the very limited number of positions assignable to each stylus. Most present systems have a capacity of three styli on each side of the paper disc.
The present invention maximizes the useable recording area on a chart. It is based on controlling the stylus such than an individual stylus can record a multiplicity of operating conditions. The system preferably incorporates a single stylus which is electronically controlled. It could however be mechanically controlled and include more than one stylus.
The recording system of this invention therefore, is for use in vehicles and records a multiplicity of operating conditions on a chart. The system includes: the combination of recording means which inscribes on the chart at essentially right angles to the chart's direction of movement; servocontrolled positioning means for positioning and moving the recording means to a recording position in response to a control signal; and control means to selectively direct different control signals for the multiplicity of operating conditions to the servocontrolled positioning means.